1. Field of the Invention
This invention relates to cementitious compositions which can be cured to form articles of construction.
2. Description of the Prior Art
Light-weight cementitious compositions are known in which the desired weight reduction over concrete is achieved by the use of light-weight aggregate. Examples of such materials can be found, for example, in U.S. Pat. No. 3,782,985. However, articles made from such materials usually possess tensile strengths which are too low for many applications.
The use of polymeric materials in concrete formulations is also known. One such material is known as polymer-impregnated concrete (PIC) and is comprised of hardened Portland cement concrete impregnated with a liquid monomeric material which is subsequently polymerized in situ. Such materials are durable and make attractive pipe, tunnel supports, bridge decks, and the like. Another system is a polymer-Portland cement concrete (PPCC) in which a monomeric or polymeric material is added to a fresh Portland cement concrete mixture, with the mixture then being cured and polymerized after placement. One another system is the polymer concrete (PC) system which contains little or no cement and no water. This system is formed by polymerizing a monomeric material with aggregate (sand, gravel, etc).
The present invention has as its object the provision of a light weight cementitious composition which has the desirable tensile and compressive strength of more traditional concretes for use as a structural building material.
Another object of the invention is the provision of such a material which is characterized by the substantial absence of aggregate such as sand and gravel, which has a high insulation value, which resists flame, which can be formed from commercially available materials, and which can be cast into a variety of structural shapes and forms.